Please consider this for adoption after checking that I didn't make mistakes in the data! Notes:

+

Notes:

* I'm conflating Lesser GPL 2.1 and Library GPL 2.0 as in the Good Licenses list.

* I'm conflating Lesser GPL 2.1 and Library GPL 2.0 as in the Good Licenses list.

−

* According to the original footnotes, LGPLv2 weakens to GPLv2+ and LGPLv3 weakens to GPLv3, in addition to the obvious weakenings of a set of versions to a subset thereof. I assume later LGPL versions would continue to weaken to the corresponding GPL versions so that LGPLv3+ weakens to GPLv3+.

+

* I realized the FSF's original table does not have "or later" in the row labels. I have asked FSF for clarification.

−

* The resulting-license data in the "copy" section is unchanged by swapping rows and columns, which makes sense, though the colors are not because they are based on the effect on the destination license.

+

* According to the original footnotes, LGPLv2 converts to GPLv2+ and LGPLv3 converts to GPLv3, in addition to the obvious conversion of a superset of versions to a subset. I assume the idea is that later LGPL versions will continue to convert to the corresponding GPL versions so that LGPLv3+ converts to GPLv3+; I have asked FSF to confirm this.

−

* The only thing I'm wondering about is the "NO" for linking GPLv2 against LGPLv3+ (which came from the FSF table); I don't see anything in the LGPLv3 text that would give this result.

+

* I am considering adding rows and columns for GPLv3 and LGPLv3 because a few Fedora packages use those licenses.

−

[[User:Mattmccutchen|Mattmccutchen]] 02:43, 29 October 2009 (UTC)

+

Once the issues are resolved, I would like to propose this table for adoption on the licensing page.

WTFPL license should link upstream

Condensed GPL Compatibility Matrix

I found the GPL compatibility matrix hard to assimilate because of its width, largely the fault of the use of "only", "or later", and "OK if you convert to" text. I prepared a condensed version that uses the licenses' short names and states the resulting license in each cell without explanatory text. I also removed the footnotes since they add no essential information. Here it is:

Destination

Source

Mode of use

GPLv2

GPLv2+

GPLv3+

LGPLv2

LGPLv2+

LGPLv3+

GPLv2

copy or link

(GPLv2)

GPLv2

NO

GPLv2

GPLv2

NO

GPLv2+

copy or link

(GPLv2)

(GPLv2+)

(GPLv3+)

GPLv2+

GPLv2+

GPLv3+

GPLv3+

copy or link

NO

GPLv3+

(GPLv3+)

GPLv3+

GPLv3+

GPLv3+

LGPLv2

copy

(GPLv2)

(GPLv2+)

(GPLv3+)

(LGPLv2)

LGPLv2

GPLv3+

LGPLv2+

copy

(GPLv2)

(GPLv2+)

(GPLv3+)

(LGPLv2)

(LGPLv2+)

(LGPLv3+)

LGPLv3+

copy

NO

GPLv3+

(GPLv3+)

GPLv3+

LGPLv3+

(LGPLv3+)

LGPLv2

link

(GPLv2)

(GPLv2+)

(GPLv3+)

(LGPLv2)

(LGPLv2+)

(LGPLv3+)

LGPLv2+

link

(GPLv2)

(GPLv2+)

(GPLv3+)

(LGPLv2)

(LGPLv2+)

(LGPLv3+)

LGPLv3+

link

NO

GPLv3+

(GPLv3+)

(LGPLv2)

(LGPLv2+)

(LGPLv3+)

Notes:

I'm conflating Lesser GPL 2.1 and Library GPL 2.0 as in the Good Licenses list.

I realized the FSF's original table does not have "or later" in the row labels. I have asked FSF for clarification.

According to the original footnotes, LGPLv2 converts to GPLv2+ and LGPLv3 converts to GPLv3, in addition to the obvious conversion of a superset of versions to a subset. I assume the idea is that later LGPL versions will continue to convert to the corresponding GPL versions so that LGPLv3+ converts to GPLv3+; I have asked FSF to confirm this.

I am considering adding rows and columns for GPLv3 and LGPLv3 because a few Fedora packages use those licenses.

Once the issues are resolved, I would like to propose this table for adoption on the licensing page.